# 在完成练习3-4~练习3-7时编写的程序之一中，使用len() 打印一条消息，指出你邀请了多少位嘉宾来共进晚餐

friends = ["Albert Einstein", "Leonhard Euler", "Archimedes"]
print(f"Dear {friends[0]}, I want to have a dinner with you.")
print(f"Dear {friends[1]}, I want to have a dinner with you.")
print(f"Dear {friends[2]}, I want to have a dinner with you.")

print("\nHey guys, I find a larger table, and we can invite more friends.")

friends.insert(0, "Euclid")
friends.insert(2, "Gauss")
friends.append("Joseph-Louis Lagrange")

print(f"\nDear {friends[0]}, I want to have a dinner with you.")
print(f"Dear {friends[1]}, I want to have a dinner with you.")
print(f"Dear {friends[2]}, I want to have a dinner with you.")
print(f"Dear {friends[3]}, I want to have a dinner with you.")
print(f"Dear {friends[4]}, I want to have a dinner with you.")
print(f"Dear {friends[5]}, I want to have a dinner with you.")

print(f"\nI totally invite {len(friends)} friends.")
